Furin belongs to the subtilisin-like proprotein convertase family. Furin is a proprotein convertase that processes latent precursor proteins into their biologically active products. It is a calcium-dependent serine endoprotease that cleaves precursor proteins at their paired basic amino acid processing sites. Some of the Furin substrates are: proparathyroid hormone, transforming growth factor beta 1 precursor, proalbumin, pro-beta-secretase, membrane type-1 matrix metalloproteinase, beta subunit of pro-nerve growth factor and von Willebrand factor.